The overall goal of the Clinical Core of the University of Kentucky Alzheimer's Disease Center (UK ADC) is to provide thoroughly evaluated, longitudinally followed, normal control subjects and Alzheimer's disease (AD) and other non-AD dementing disorders patients for innovative research studies at UK, other ADCs and institutions studying AD and aging. This Core will maintain a normal control population of 500 initially normal aged subjects who will be followed longitudinally to autopsy (all have prearranged autopsies). The major emphases will be on studies of normal aging and transition to preclinical AD, mild cognitive impairment (MCI), and early AD. Control participants will be evaluated annually with medical, neurologic, and neuropsychological tests to define subtle changes in cognitive and neurologic functions. A developmental study will be carried out to attempt to define the theoretical entity, preclinical AD, in this population. This Core will maintain a Dementia Research Clinic of 200 subjects with dementing disorders who will be followed longitudinally to autopsy (all have prearranged autopsies). Emphasis will be placed on recruiting MCI, early AD, and mixed dementia (AD/vascular dementia, AD/DLB, Parkinson's Disease Dementia) patients. Dementia Research Clinic patients undergo the same thorough annual evaluation as our control subjects. The detailed evaluation of control and dementia subjects provides a database for use by UK investigators associated with our Center and investigators at other ADCs and institutions. Longitudinally followed control subjects and MCI and early AD patients will provide important data about the course and progression of AD. The Clinical Core will expand and maintain a satellite clinic for African Americans, the Kentucky Clinic North Minority Satellite, in Lexington to provide longitudinal follow and broadening research opportunities for an understudied population. This Core will also obtain serum, plasma, buffy coats and CSF from normal control subjects, MCI and early AD patients for use by investigators. The Core will participate in the NIA AD neuroimaging initiative, NACC funded studies, ADCS trials, and industry sponsored drug trials. The uniform data set and the minimum data set are collected by this Core and submitted to NACC in a timely fashion by the Biostatistics and Data Management Core. The close relationship between the Clinical Core and the Neuropathology Core allows for unique clinical-pathological correlation studies on longitudinally followed subjects to better understand normal aging and transition to MCI and AD.